[Blimp Net] Add EngineAuthHandler.

blimp/common/proto/protocol_control.proto

Index: blimp/common/proto/protocol_control.proto
diff --git a/blimp/common/proto/size.proto b/blimp/common/proto/protocol_control.proto
similarity index 51%
copy from blimp/common/proto/size.proto
copy to blimp/common/proto/protocol_control.proto
index f6ba801495df51dbe000a44b4369861105d1ba3d..a5b2018655b1f430dd50169d52a5bc55ed991d57 100644
--- a/blimp/common/proto/size.proto
+++ b/blimp/common/proto/protocol_control.proto
@@ -8,10 +8,9 @@ option optimize_for = LITE_RUNTIME;
 
 package blimp;
 
-// Contains display information that represents resize events coming from the
-// client device.
-message SizeMessage {
-  optional uint64 width = 1;
-  optional uint64 height = 2;
+// Contains Client->Engine information to establish a authenticated connection.

[Kevin M, 2015/12/03 19:11:36]

This won't be used bidirectionally?

[Kevin M, 2015/12/03 23:12:05]

?

[haibinlu, 2015/12/03 23:42:20]

Done.

+message ProtocolControlMessage {

[Kevin M, 2015/12/03 19:11:36]

Add an inner Type enum to distinguish this message?

[haibinlu, 2015/12/03 22:28:35]

what are other types?

[Kevin M, 2015/12/03 23:12:05]

e.g. checkpoint acks, session recovery message. We'll add these later, but we
can go with a single-entry type enum for now.

ISTM that a minimal message structure won't save us time even in the short term;
we'll have to refactor it in a matter of a couple weeks to support other
subtypes.

[haibinlu, 2015/12/03 23:42:20]

Done.

+  optional string client_token = 1;
+  optional int32 protocol_version = 2;
+  // TODO(haibinlu): add checkpoints.
 }
-